Clark forklift brake systems are fairly straight forward to work on. Some have wet brakes, others utilize traditional brake shoe brake set ups. This tutorial will show you how to replace brakes on a Clark forklift with brake shoes.
Forklift brake systems typically use a master cylinder often mounted beneath the operator floor panel. Remove the floor panels, find the master cylinder and go to work. This tutorial will show the replacement of a master cylinder on a Hyster 5000 pound forklift.
One of the most common forklift complaints from forklift operators is a noticeable propane gas smell around the forklift. Frequently forklift operators will call service companies complaining that their forklift has a leak. Often the problem is not with the forklift but with the propane tank.
This tutorial will show how to replace 2 o-rings on the propane tank and eliminate one of the most common complaints from forklift operators.
The model J regulator is the most popular LPG regulator on the market today, yet it is no longer used in current models of forklifts due to emissions regulations.
Impco model J regulators are found in a most brands of forklifts along with other LPG powered equipment like Tennant or American Lincoln scrubber units and even Zamboni ice resurfacers.
Inside the model J are diaphragms made of hydrin or silicone. These wear out or tear and need to be replaced. The first decision you’ll have to make is if you want to replace the entire model J unit or rebuild the unit with a repair kit. Either decision is fine, it just depends on how you value your time.
You will see in the tutorial below that rebuilding a model J is pretty simple. There are times when a model J might be mounted inside a forklift where it’s easier to rebuild the unit instead replacing the entire unit. It just depends on the location of the model J.
One more note. Model J is Impco’s designation for an entire series of LPG regulators. There’s a method to how the Impco part numbers work:
Model JB = Model J with Blue spring. Blue spring units have Neg. 0.37 kPa pressure. This is the standard and most common model J.
Model JO = Model J with Orange spring. Orange spring units have Neg. 0.12 kPa pressure. This is the lease common model J. You should stick with the model J that is already installed in your forklift.
After the letters JB or JO, you sometimes see a -2 like this: JB-2. The -2 indicates the diaphragms are manufactured from silicone. No letter means the diaphragms are made from black hydrin rubber. Silicone (yellow) diaphragm material is the optional upgrade material that provides excellent flexibility in cold weather climates and is more resistant to chemical contamination. They can be used interchangeably, if you want to upgrade, go with the silicone material.
Remove screws from front of unit. The screws are typically 9-32 x 7/8″ Torx style
Remove diaphragm from inside cover
Remove lever. Screw is also a Torx screw
Remove the screws from the back of the model J unit.
Take the halves apart and remove the old diaphragm.
Forklift brakes are fairly straight forward to replace, especially for someone with automotive experience. Forklift brake systems are traditional brake drum/brake shoe set ups, very similar to what an automobile would use in the 1960s and 1970s. Most forklift manufacturers recommend a complete brake inspection every 2000 operating hours. Brake system (shoes, drum, etc) are wear items are there’s no typical lifespan. If you use your brakes a lot, you’ll need to replace brake shoes more frequently. It probably goes without saying but brakes are only on the front axle on forklifts. The rear axle does not have brakes.
This tutorial walks you through a typical forklift brake job. The example forklift was a Toyota 6FGCU18 but the same system will be found on other brands of forklifts as well such as Hyster, Yale, CAT, Mitsubishi and others. Wet disk brakes are a thing in the forklift industry but somewhat rare. Clark, Doosan, and CAT used wet disk brakes throughout the years. If you have a wet disk brake set up, the below tutorial will NOT apply for your forklift.